Jack Straw has decided to introduce yet another criminal offence, adding to the 3,000 new crimes Labour has introduced since it came to power in 1997. This latest offence will prohibit the incitement of homophobic hatred.

It is intended to help tackle anti-queer prejudice, which is a good intention. But will this legislation work? Is it necessary? Might it not lead to infringements of free speech? Are there more effective ways to challenge homophobia and other hateful incitements?

A much more important issue is the fact that the government, police and prosecution service are failing to enforce the laws prohibiting the incitement of actual violence and murder against the lesbian, gay, bisexual and transgender communities. Inciting violence and murder is much worse, in my view, than inciting hate. Yet the relevant laws are often not enforced. Why not?

On the positive side, the proposed new legislation will bring the statutes governing incitements to hatred on the ground of sexual orientation into line with the long-standing laws prohibiting the incitement of hate based on a person's race. In other words, it will establish parity in law with regard to stirring up hatred. But only partially. Many forms of incitement to hatred will continue to not be covered by criminal sanctions. These include incitements to hatred against asylum seekers, women, disabled people, travellers, ex-prisoners, people with HIV and so on.

If there are going to be laws against inciting hatred, they should be universal and prohibit all incitements to hatred - not just some. Singling out race hate and homo hate for special legal penalties strikes me as unfair and undesirable. It creates resentment among social groups who are not protected by such laws, which is bad for community cohesion. My view is very simple: everyone should be equal before the law, in which case all incitements of hatred should be an offence.

There are sound arguments to justify a prohibition on inciting hatred against vulnerable minorities who have a history of suffering persecution and prejudice. It is deemed to be a method of protecting them and creating a social atmosphere where they have redress against their tormentors.

Another argument, for which I have considerable sympathy, is that hatred is the gateway to discrimination, harassment and violence. It is the psychological foundation for serious, harmful criminal acts. Without the precondition of hatred, there would be no hate-motivated violent attacks on the black, Jewish and gay communities. In other words, if we can stop hatred and hate-mongers, we will stop the prejudice that often spills over into hateful, damaging acts, such as racist and queer-bashing murders. On these grounds, laws against inciting hatred are ethically justified and have practical benefits.

The downside of incitement to hatred prohibitions is that they risk infringing freedom of speech. Who decides what constitutes hatred? It is a grey, disputable area. Defining hatred is difficult to determine in a way that will satisfy everyone. Different people have different interpretations of hatred. Is causing offence, or even distress, an incitement to hatred? What about ridiculing and mocking someone's beliefs? Is that hateful? Where do you draw the line between legitimate robust criticism and satire, and illegitimate, criminal incitement of hatred? It isn't simple and straightforward.

Many people say that these concerns are unfounded. They point to Ireland which has had comprehensive legislation banning the incitement of hatred since 1989. The law has been applied lightly and there has been no crackdown on free speech. It is said that the police and courts in the UK would show similar restraint. They will only go after the most excessively hateful and damaging incitements.

But can we be so sure? After all, similar laws have been abused in the recent past. An Oxford student was arrested and fined under the laws against public disorder for making a joke about a policeman's horse being gay. The officers construed this joke as a homophobic remark and nailed the student under the already existing wide-sweep public order legislation which bans behaviour likely to cause harassment, alarm or distress. It is not clear whether it was the police officer or the horse that was supposedly offended by the student's off-the-cuff quip.

In the Australian state of Victoria, the law banning incitement to religious hatred has led to Christians and Muslims accusing one another of inciting hatred and bringing legal actions against each other, which has only served to inflame community relations.

In Bournemouth, the lay preacher, Harry Hammond, was convicted in 2001 under the public order laws for holding up a sign saying "Stop homosexuality, stop lesbianism." His arrest and conviction was, I believe, an outrageous infringement of free speech. Harry was, of course, a notorious homophobe. His prejudice needed to be rebutted, but not by making him a criminal and a martyr.

The same goes for all prejudice, whatever the motive and whoever the perpetrator. The best way to tackle prejudice is by presenting facts and using reasoned arguments, to break down ignorance and ill-will.

All incitements to hatred should be treated with the same zero tolerance. But not, in my opinion, by means of criminal sanctions. Free speech is precious. It should be limited only in exceptional circumstances - when it slips into inciting violence and murder.

The most effective way to diffuse hatred is by education and debate. Our schools, media and public figures have a vital role to play in challenging bigotry, encouraging social solidarity and helping to promote understanding and empathy with others.

Prevention is better than cure. Education and debate seeks to prevent hatred in the first place, whereas criminalisation seeks to punish the offender after he or she has already stirred hatred. It is shutting the stable door after the horse has bolted.

My real gripe is that inciting violence is much more serious than inciting hatred. Yet the laws prohibiting the advocacy and encouragement of homophobic violence are often not enforced.

For nearly two decades, despite repeated appeals from the gay community, the government, police and prosecution service have allowed record stores and radio stations to promote "murder music" songs inciting the killing of queers. Jamaican artists such as Buju Banton, Beenie Man and Bounty Killa have released CDs that openly encourage and glorify the shooting, burning, hanging and drowning of gay and lesbian people.

Inciting murder is a criminal offence under long-standing laws. Yet these songs have been given airplay on mainstream radio stations such as the BBC, as well as on local black pirate stations. The tracks are sold openly in many record stores and via online websites such as Amazon. The police have made no attempt to take action against the record companies and distributors, the record stores and websites, and the radio stations and deejays.

The police and Crown Prosecution Service (CPS) would never take such a hands-off approach to people who incited violence against black or Jewish people. Why the double standards?

Likewise, some fundamentalist Muslim clerics, on the extremist wing of Islam, openly urge the killing of gay people, unchaste women and Muslims who turn away from their faith. In east London in 2005, hate preacher Abdul Muhid of the pro-jihad Saviour Sect, urged the murder of homosexuals. Despite witnesses willing to go to court, the Crown Prosecution Service refused to prosecute him. Yet when the Islamist Abdullah el-Faisal incited the murder of Jews, Hindus and Americans in 2003 he was promptly arrested, convicted and jailed. More double standards.

The non-prosecution of Muslim clerics who incite the murder of gay people is a tragic betrayal of vulnerable gay and lesbian Muslims. They live in fear of the homophobic violence that is being stirred up by Islamist extremists. What signal does this official hands-off attitude send to queer Muslims? That the government does not care about their suffering? Police and CPS inaction gives homophobic persecutors a de facto green light to continue their violent threats.

Introducing legislation prohibiting the incitement of homophobic hatred seems a bit amiss when already-existing laws are not being enforced against the much more serious crimes of inciting violence and murder. Please, Mr Straw, ensure the enforcement of the current laws before you start introducing new ones.